Thread: Engine Case Venting

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I'm getting myself confused once again. I had a friend over today and we were going over everything before I start my engine up for break in. It's a 383 SBC that I have built up from scratch.

We started wondering how the case is vented and I don't think it is, I overlooked this during the build. My valve covers have a hole that I put in a push-in style PCV valve (that I actually was thinking was a vent as well), and the other side has a push in oil cap. So do I need to drill in another hole and add in some sort of vent, I actually have a new one I had forgotten about.

Thanks,
Sean

I want to start this up soon!!!!!!!!!

The crank case needs some where to draw fresh air from. You should have an inlet on one side and the pcv valve drawing on the other side.

This is what I have on the one side:

http://www.speedwaymotors.com/Billet...alve,7184.html

Is that enough, I figure I should have something on the other side.

Sean

The one you have should be plumbed to the base of the carb. You need one without the PCV valve plumbed to the underneath of the air cleaner.

Hhhmmmm.....I got this one like you said. So if I understand I need another one with the spigot and then I have to make some way to run it into the air cleaner....my air intake doesn't have any connections for that. Is there another way, I guess just a breather is no good then is it??

This is what I have but for the single carb set-up:

http://www.speedwaymotors.com/Gasser...oops,3788.html

I'd post pictures but my wife is on my computer and won't trade me.

Sean

A regular breather on the other side will work, but IMHO it is not as efficient open to to air as one plumbed into the air filter.

Okay thanks, I'll try to get this sorted out.

Sean

The point behind a vent pipe to the air cleaner is, the air filter cleans the air better than a bitty little vented cap can. Also, under some conditions, fumes come out of the vent, rather than going in. With it going to the intake, the fumes get burned in the engine rather than escaping into the atmosphere. Cleaner, and less stink for the occupants, especially for an open car or one with a louvered hood.

I don't have a air cleaner, so I ran the pvc out of the valley of the intake then returned it threw a intake runner. My motor is 412" and it satisfies any blow by I have. Just another way of doing it. The only other vent is threw the oil filler cap in the intake. There are no holes in my valve covers.
Ken

Here's what I did. My air cleaner didn't have a hole so I drilled one on the bottom, pushed the hose throught the hole and used a small clamp around the hose so it wouldn't slip out. Works great.

a good pcv sys. has two parts the pcv uses manifold vacuum to create a negative pressure in the crankcase and remove blow by it has a metered orifice calibrated to eng. displacement the second part is commonly called a kv tube it goes to the air cleaner under heavy load and at w.o.t. there is no manifold vacuum but there is a low pressure inside the air cleaner this handles the crankcase pressure then any body has never done it before should hook up a vacuum gage temporally inside there car and drive around for a week or so you will learn a lot about eng. operation and kind of fun watching eng. load vs throttle setting ....ted

Thanks for all the input guys, I think the easiest way for me to do this is like Chevy 37. I don't even recognize any parts on your car Ken but I'm sure you know what you're talking about. I gotta look at that again.

Thanks for the background R Pope and Ted that makes some sense to me now.

Sean